PULSCAR ANALYSIS - P0606 (CONTROL MODULE PROCESSOR) AND ENGINE / POWERTRAIN CONTROL MODULE FAULTS IN NHTSA'S PUBLIC FILES PulsCar analysis of NHTSA public data, October 2026. License: CC BY 4.0 Attribution: "PulsCar analysis of NHTSA public data, October 2026." Published alongside https://www.pulscar.io/blog/p0606-code ------------------------------------------------------------------------------ Prepared October 2026. Source data: NHTSA public flat files (complaints received 1 January 2015 to 4 October 2026 - the latest received date in the files; manufacturer communications; recalls since 2010) and documents downloaded one at a time from static.nhtsa.gov. 1. Complaints (4,655) First search (926): every complaint whose narrative names P0601 to P0607 by any spelling we searched (a letter O for zero, a space, hyphen or period after the P, the suffix 00, or a bare 601 to 607 after "code", "DTC", "error", "CEL", "coded" or "fault"), or names an engine or powertrain control module in owners' words (ECM, PCM, ECU, engine control module/unit, powertrain control module/unit, engine computer, main computer and similar) within about 50 characters of a word of failure and also mentions a check-engine light, a code, a stall, a no-start or limp/reduced power. Second search (1,199): an independent search of the same file for what the first one missed, run after the first batch was sorted: the two-word spelling "power train control module", generic names (engine computer, engine module, electronic control module, DME), code forms with a suffix (P060194) and the codes P060A to P060C, P061A to P061E and P062F, and failure wording outside the 50-character window. Every complaint it proposed that names the module as failed, faulty, diagnosed, coded, damaged, not communicating or the problem of a recall or campaign, or names one of those codes, was added. Third batch (2,530): the same second search found 2,530 further complaints that name an engine computer only as replaced, updated or reprogrammed, with no word of failure near it. They were first set aside as answering a different question; on 14 October 2026 that decision was reversed and they were sorted too, twice, independently, under addendum 2 to the sorting rules, which was fixed (dated and locked) before any of them was sorted. found_by in the complaints file says which search found each complaint. Sorting: the sorting rules (codebook.txt) were written, dated and locked before any complaint was sorted; an addendum for the second batch and a second addendum for the third batch were each dated and locked before the batch they cover was sorted. Every complaint was sorted twice, independently, by the same written rules, each time from the rules alone, without sight of the other sorting, from a window of the narrative around the matching words (the whole narrative when nothing matched). One category (N not an engine or powertrain control module fault on this vehicle; M module named by a shop or replaced; F software or a campaign procedure only; W power, ground, battery, alternator, connector or wiring; L water, coolant, oil or corrosion; O another cause; K checked and cleared; U no diagnosis or repair stated) and four yes/no flags (stall, nostart, recall, returned) per complaint. Agreement over all 4,655: category 4,051 (87.0%); stall 4,434 (95.3%); nostart 4,593 (98.7%); recall 4,391 (94.3%); returned 4,417 (94.9%). The third batch alone: category 2,139 of 2,530 (84.5%). Settling: every disagreement (1,074 on any field, 604 of them on the main category) was read and settled by one of the written rules R1 to R34 (listed in codebook.txt, with R35 added after the last check); the rule applied is in the rule_applied column. Last check: after settling, every complaint was checked again against its full text (the sorters had seen a window of the narrative, not all of it) under the same written rules. That check corrected 773 complaints (289 main categories, 313 stall, 100 nostart, 214 recall and 41 returned flags, counting all changes); rows it changed say "changed in consistency pass" in the resolution column, with the rule in rule_applied. The added complaints were checked in full against all the rules; the older ones and those marked not relevant were checked for their flags and for causes named later (a not-relevant complaint was moved into the set only under R30). One reading was written down as rule R35 (see codebook.txt): when a stated repair, replacement or reflash did not fix the problem and no other cause is named, the complaint keeps the category of that repair and the returned flag records the failure. About 100 complaints settled earlier under R5 or R27 (category U, returned yes) were not all re-sorted under it and may sit in U although they state one failed repair. Result: 4,032 relevant, 623 not relevant. Counts are counts of complaints, not cars. A complaint is evidence that an owner wrote to NHTSA; nothing here is a failure rate. 2. Documents (665 files, 579 distinct documents) First search: NHTSA's index of manufacturer communications, entries whose summary names P0601 to P0607 or a control-module processor, internal-fault or similar wording: 499 listed, 441 with a PDF (58 have none). Second search: 278 more listed by the independent search, 223 with a PDF (55 have none). One file number has two PDFs, so 665 files. Reading: 316 representative documents (one per family of revisions and look-alikes whose text is at least 60% the same) were read in full; 266 further files (revisions, copies and look-alikes) were compared with the representative line by line; 83 files (documents that name none of the codes and mention a control module only in passing) were checked for the codes and the module's name in their own text and were not read through. 18 files with no readable text (all of them among the 83 files checked only for the codes) were read from images of their pages; that read added one paper that prints P0606 (an Audi bulletin of 11 November 2025 for the 2024-2025 SQ7 and SQ8), two that print it with a suffix, and 13 that print other codes of the same family. Every verbatim quotation in the article was checked against the text of the named document. Four Ford recalls and one Audi recall cited in the article were read from their NHTSA filings; recall years come from those filings and NHTSA's recall letters. Model years, engines, build dates and coverage terms are as printed in the documents, never taken from NHTSA's index, which expands years. Coverage status "as of September 2026" is the authors' computation from printed terms. exact_copy_of marks exact copies (same text as another file); 86 of the 665 files are exact copies, leaving 579 distinct documents. The columns names_p060x_in_own_text mark the plain code only (the code followed by a non-digit); the 26 files that print P0606 only with a suffix such as P060600, and the 80 that print any of P0601 to P0607 only that way, are counted in the article's 146 and 417 but not marked in these columns. 3. Owner-reported amounts (251 figures in 236 complaints) One written inclusion rule (fixed before the figures were decided): INCLUDE a dollar figure when the owner states it as a price, charge, bill or quote for diagnosing, repairing, reprogramming or replacing the engine/powertrain control module (ECM/PCM/ECU), its power, ground, connector or wiring at the module, or a diagnostic fee asked for that module event, on THIS vehicle. EXCLUDE: mileage written as 'NNk'; vehicle value, payments, trade-in, loans or refund/compensation requests; repairs of other systems (transmission, engine internals, catalytic converter, sensors, tires, etc.); totals that mix module work and other work unless the narrative attributes the figure to the module; restatements of a figure already counted in the same narrative (count once); hypothetical or other owners' costs; tow charges; rental cars. STATUS (from the owner's own words): paid (paid / cost me / spent), billed (bill, invoice, charged, cost), quoted (told, quoted, estimate, wants, would cost, needs), offered, not stated. GROUP: module (module replacement, part and/or labor), software (reprogramming/flash/programming fee), power (battery/ground/connector/harness at the module), diag (diagnostic fee), mixed (module plus other work in one figure), unspecified (a repair of the module fault whose parts are not named). About 830 candidate figures were looked at and 251 kept; each exclusion has a short reason in our notes. One narrative filed twice by the same owner is counted once. The rule was applied to the complaints of the first two batches (926 and 1,199) and, after the third batch was sorted, to the relevant complaints of that batch, under the same written text; a figure that names module work together with other work in one sum is shown only in the separate group "mixed" and never in the module, software, power or diagnostic groups; a sum that adds a transmission or engine-internal repair or a tow, a general or hypothetical cost, or a figure that does not name the module's work, is excluded. 4. Limits The complaint file holds the cases where an owner wrote to NHTSA, in the owner's words, with no verification; owners whose trouble ended are mostly not in it. The shares reported (for example how many module replacements were followed by a return of the problem) describe the complaints, not all cars. Checks of random samples against the written rules: before the last check, 19 of 85 sampled complaints of the third batch had a wrong category or flag; after it, 100 sampled complaints (40 from the first two searches, 40 from the third batch, 20 marked not relevant) had a clear error in 2, 5 and 0 of them, and 28 more were doubtful. Shares are therefore approximate, and those from the third batch the least certain. The third batch (complaints that only mention a replaced or updated module) was sorted with lower agreement than the rest, because owners often do not say why a module was updated. The document set holds what NHTSA's index lists; a maker paper that is not in the index is not in it. P0606 appears in papers for engine, transmission, brake, body, lighting, transfer-case and hybrid computers; the complaint set follows the engine and powertrain module, and the P0606 complaints about other modules are marked by their category and make.